GB638504A - Polycyclic diketopyrimidines - Google Patents

Abstract

Polycyclic diketopyrimidines, useful as intermediates for merocyanine dyes, and of the general formula <FORM:0638504/IV (b)/1> wherein Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing two hereto atoms (e.g. of the thiazole, thiazoline, selenazoline, pyrazolone or thiazine series), R is an aryl group of the benzene or naphthalene series (e.g. phenyl, substituted phenyl, such as chlorophenyl or xylyl, naphthyl or diphenyl), R1 represents hydrogen or an acyl group, M represents a methine group and n is 1, 3 or 5, and wherein the central methine group may be substituted by chlorine or bromine when n is 3, are manufactured by reacting a compound of the general formula <FORM:0638504/IV (b)/2> with a compound of the general formula R11NH-(M)n=N-R111 or a salt thereof (where R11 and R111 represent aryl groups of the benzene or naphthalene series), the reaction optionally being effected in the presence of an organic acid anhydride (e.g. acetic, propionic, butyric or benzoic anhydride) or the products subsequently treated therewith (when R1 is to be acyl). The reaction in the absence of an acid anhydride is effected, when n is 1, in the presence of a diluent (e.g. kerosene), or, when n is 3 or 5, in the presence of an alcohol (e.g. ethanol or n or iso-propanol) and a strong organic base (e.g. triethylamine, piperidine, diethylamine, N - methylpiperidine, or triethanolamine). Suitable pyrimidine starting materials are obtainable by condensing ethyl malonate, in the presence of alcoholic sodium ethylate, with a tautomeric compound of the general formula <FORM:0638504/IV (b)/3> e.g. 2-aminothiazoline, 2-aminoselenazoline, 2-aminodihydrothiazine, 2-amino-5-methylthiazoline, 2-amino-4-phenylthiazoline, 2-aminohexahydrobenzthiazole or 3-phenyl-5-aminopyrazolone. The other starting materials are diaryl-formamidines (n=1), e.g. diphenyl-, dinaphthyl-and dixylyl-formamidines; arylaminoacrolein anils and their salts (n=3), e.g. b -anilinoacrolein anil and its hydrochloride and their a -chloro and a -bromo derivatives; and o -arylamino-D 2,4-pentadienal anils and their salts (n=5), e.g. glutaconic aldehyde dianil hydrochloride. Examples illustrate the use of certain of the reagents specified above. Specifications 470,725, 517,769 and 637,648 are referred to. The Specification as open to inspection under Sect. 91 comprises also the manufacture of compounds of the first general formula above in which the heterocyclic ring completed by the atoms represented by Z does not contain a second hetero-atom, e.g. those in which the said ring is of the pyridine or quinoline series. An additional starting material specified is the compound obtained by condensation of ethyl malonate with 2-aminopyridine. Pyridine is additionally specified as a basic condensing agent. This subject-matter does not appear in the Specification as accepted.